Your traffic offence has nothing to do with Switzerland. As previously stated, you will be charged a fee by the Swiss, but won't receive further punishment from Switzerland. However, I understand that as the French have suspended your licence, you no longer have a licence to drive anywhere until they give it back -- but I'm happy to be corrected on that last part.

Road traffic law §16c (no English version available):

Withdrawal of driving licence after an offence abroad

1 After a violation abroad, the learning driving licence or driving licence will be withdrawn if:

a. a driving ban has been imposed abroad; and
b. the infringement is of medium or serious nature in accordance with Articles 16b and 16c.

2 When determining the withdrawal period, the effects of the foreign driving ban on the person concerned shall be adequately taken into account. The withdrawal period may be shorter than the minimum withdrawal period. In the case of persons for whom no data on administrative measures (Art. 89c letter d) are contained in the Traffic Licensing Information System, the withdrawal period may not exceed the duration of the driving ban imposed abroad.

"In the case of persons for whom no data on administrative measures (Art. 89c letter d) are contained in the Traffic Licensing Information System"


What does that mean? No previous recorded bans in CH?

Quick update after speaking to a lawyer. I should definitely expect to lose my license in Switzerland. Likely for the same length, possibly less. But not less than 3 months. He confirmed that Swiss will not fine me. They will charge me a 200-300chf admin fee, but this is apparently covered by my legal insurance. Very relieved!

Yes, that is what my lawyer confirmed. If I have no previous bans, then the Swiss cannot ban me longer than the French. "normal" speeding tickets resulting in fines don't count against you.

No bans and also no warnings from the Swiss license authority.
Simple fines do not count. They are anonymous and not recorded.

Administrative measures are supposedly(*) purged five or ten years after the most recent measure.

Admonishments for example are to be considered for five years. So if you were admonished every four years, all of them would be visible and taken into consideration. If however you received one every six years, at worst one admonishemt would be considered.

OTOH temporary license suspensions are considered for ten years.

(*) "Supposedly" because multiple instances have come to light where police records weren't actually deleted as legally mandated but rather, old data were merely marked as old or similar.